This invention relates to telemanipulation using telepresence, and more particularly to applications of telemanipulation to laparoscopic surgery.
A telemanipulation system allows an operator to manipulate objects located in a workspace from a remote control operator""s station. For example, in a laparoscopic abdominal surgery procedure, the patient""s abdomen is insufflated with gas, and cannulas are passed through small incisions to provide entry ports for laparoscopic surgical instruments. Laparoscopic surgical instruments include an image capture means for viewing the surgical field and working tools, such as forceps or scissors. The working tools are similar to those used in open surgery, except that the working end of each tool is separated from its handle by an extension tube. The surgeon performs surgery by sliding the instruments through the cannulas and manipulating them inside the abdomen while referencing a displayed image of the interior of the abdomen. Surgery by telepresence, that is, from a remote location by means of remote control of the surgical instruments, is a next step. A surgeon is ideally able to perform surgery through telepresence, which, unlike other techniques of remote manipulation, gives the surgeon the feeling that he is in direct control of the instruments, even though he only has remote control of the instruments and view via the displayed image.
The effectiveness of telepresence derives in great measure from the illusion that the remote manipulators are perceived by the operator of the system to be emerging from the hand control devices located at the remote operator""s station. If the image capture means, such as a camera or laparoscope, are placed in a position with respect to the manipulators that differs significantly from the anthropomorphic relationship of the eyes and hands, the manipulators will appear to be located away from the operator""s hand controls. This will cause the manipulators to move in an awkward manner relative to the viewing position, inhibiting the operator""s ability to control them with dexterity and rapidity. However, it is often unavoidable in applications such as laparoscopic surgery to move the laparoscope in order to obtain the best possible image of the abdominal cavity.
Thus, a technique is needed for providing to the operator the sense of direct hand control of the remote manipulator, even in the presence of a substantially displaced imaging device, such that the operator feels as if he is viewing the workspace in true presence.
According to the invention, in a telemanipulation system for manipulating objects located in a workspace at a remote worksite by an operator at an operator""s station, such as in a remote surgical system, the remote worksite having a manipulator or pair of manipulators each with an end effector for manipulating an object at the workspace, such as a body cavity, a controller including a hand control at the control operator""s station for remote control of the manipulators, an image capture means, such as a camera, for capturing in real-time an image of the workspace, and image producing means for reproducing a viewable image with sufficient feedback to give the appearance to the control operator of real-time control over the object at the workspace, the improvement wherein means are provided for sensing position of the image capture means relative to the end effector and means are provided for transforming the viewable real-time image into a perspective image with correlated manipulation of the end effector by the hand control means such that the operator can manipulate the end effector and the manipulator as if viewing the workspace in substantially true presence. By true presence, it is meant that the presentation of an image is a true perspective image simulating the viewpoint of an operator. Image transformation according to the invention includes rotation, translation and perspective correction.
The invention will be better understood by reference to the following detailed description in connection with the accompanying drawings.